Method to enhance yeast growth for fermentative bioproduct production, and nutrient composition for same

Abstract

A method for enhancing yeast growth for bioproduct production is described. A method for fermentative bioproduct production also is provided. A nutrient composition used in the methods also is described. A liquid mixture containing the nutrient composition, yeast culture (or fungi, algae, or bacteria culture), and sugars also is provided.

What is claimed is: 
     
       1. A method for enhancing yeast growth for bioproduct production, comprising:
 culturing at least one yeast in a growth medium containing a nutrient composition to obtain a propagated yeast culture, wherein the nutrient composition comprises corn steep liquor and at least one of (a) at least one antifoaming agent, or (b) at least one surfactant, or any combination thereof, 
 wherein the at least one yeast is  Saccharomyces cerevisiae, Saccharomyces pastorianus  ( carlsbergiensis ),  Kluyveromyces lactis, Kluyveromyces fragilis, Fusarium oxysporum , or any combination thereof, 
 wherein the at least one organic antifoaming agent is a polyglycol, a blend of polyglycol and silicone, a fatty acid ethoxylate, an ethoxylated fatty amine, or any combination thereof, and 
 wherein the at least one surfactant is a nonionic surfactant that is an ethoxylated sorbitan ester, a glyceride ethoxylate, an ethoxylated castor oil, an alcohol ethoxylate, an alkylphenol ethoxylate, a phenol ethoxylate, an amide ethoxylate, a fatty acid ethoxylate, a fatty amine ethoxylate, a fatty amide ethoxylate, a fatty mono or di-ethanolamide, an alkyl glycoside, a polyethylene glycol (PEG), an acetylenic glycol, a polypropylene glycol (PPG), a poloxamer, an alkali metal arylsulfonate, an ethoxylated fatty amide, or any combination thereof, 
 and wherein a) addition of the nutrient composition results in an increased yeast concentration in the propagation and fermentation tanks of at least 3 million cells per gram as compared to a yeast concentration in the propagation and fermentation tanks wherein the culturing is done with addition of only the same amount of said corn steep liquor and without the at least one antifoaming agent, or 
 wherein b) addition of the nutrient composition results in an increased ethanol concentration in the fermented biomass of at least 1% w/v as compared to an ethanol concentration in the propagation and fermentation tanks wherein the culturing is done with addition of only the same amount of corn steep liquor and without the at least one antifoaming agent and at least one surfactant, or both. 
 
     
     
       2. The method of  claim 1 , wherein the nutrient composition comprises the at least one surfactant. 
     
     
       3. The method of  claim 1 , wherein the at least one antifoaming agent is present. 
     
     
       4. The method of  claim 3 , wherein the at least one antifoaming agent is at least one surfactant that has an HLB value of from 1 to 5. 
     
     
       5. The method of  claim 2 , wherein the at least one surfactant is said ethoxylated sorbitan ester (polysorbate). 
     
     
       6. The method of  claim 2 , wherein the at least one surfactant has an HLB value of from 2 to 39. 
     
     
       7. The method of  claim 2 , wherein the at least one surfactant has an HLB value of from 7 to 25. 
     
     
       8. The method of  claim 2 , wherein the nutrient composition comprises from 95% to 99.9% by weight of the corn steep liquor, and at least one of (a) from 0.1% (w/v) to 5.0% (w/v) of the at least one antifoaming agent, or (b) from 0.1% (w/v) to 5.0% (w/v) of the at least one surfactant, or any combination of (a) and (b), based on total solids weight of the composition. 
     
     
       9. The method of  claim 1 , wherein the culturing comprises culturing a mixture containing from 0.01% to 50.00% by weight of the at least one yeast and from 99.99% to 50.00% by weight of the nutrient composition, based on the weight of the mixture. 
     
     
       10. The method of  claim 1 , wherein addition of the nutrient composition results in an increased yeast concentration in the propagated yeast culture of at least 25% more on a cells per unit weight basis as compared to a yeast concentration in the propagated yeast culture wherein the culturing is done with addition of only the same amount of said corn steep liquor and without the at least one antifoaming agent. 
     
     
       11. The method of  claim 2 , wherein addition of the nutrient composition results in an increased yeast concentration in the propagated yeast culture of at least 25% more on a cells per unit weight basis as compared to a yeast concentration in the propagated yeast culture wherein the culturing is done with addition of only the same amount of said corn steep liquor and without the at least one surfactant and the at least one antifoaming agent. 
     
     
       12. A method for fermentative bioproduct production, comprising: culturing at least one yeast in a growth medium containing a nutrient composition to obtain a propagated yeast culture, wherein the nutrient composition comprises corn steep liquor and at least one of (a) at least one antifoaming agent wherein the at least one organic antifoaming agent is a polyglycol, a blend of polyglycol and silicone, a fatty acid ethoxylate, an ethoxylated fatty amine, or any combination thereof, or (b) at least one surfactant wherein the at least one surfactant is a nonionic surfactant that is an ethoxylated sorbitan ester, a glyceride ethoxylate, an ethoxylated castor oil, an alcohol ethoxylate, an alkylphenol ethoxylate, a phenol ethoxylate, an amide ethoxylate, a fatty acid ethoxylate, a fatty amine ethoxylate, a fatty amide ethoxylate, a fatty mono or di-ethanolamide, an alkyl glycoside, a polyethylene glycol (PEG), an acetylenic glycol, a polypropylene glycol (PPG), a poloxamer, an alkali metal arylsulfonate, an ethoxylated fatty amide, or any combination thereof,
 wherein said at least one yeast comprises  Saccharomyces cerevisiae, Saccharomyces pastorianus  ( carlsbergiensis ),  Kluyveromyces lactis, Kluyveromyces fragilis, Fusarium oxysporum , or any combinations thereof; 
 inoculating a fermentation substrate with the propagated yeast culture to produce a fermentable biomass; 
 fermenting the fermentable biomass to produce a fermented biomass comprising at least one bioproduct and non-fermented solids content; and 
 separating at least a portion of the at least one bioproduct from the solids content, 
 wherein a) addition of the nutrient composition results in an increased yeast concentration in the propagation and fermentation tanks of at least 3 million cells per gram as compared to a yeast concentration in the propagation and fermentation tanks wherein the culturing is done with addition of only the same amount of said corn steep liquor and without the at least one antifoaming agent, or 
 wherein b) addition of the nutrient composition results in an increased ethanol concentration in the fermented biomass of at least 1% w/v as compared to an ethanol concentration in the propagation and fermentation tanks wherein the culturing is done with addition of only the same amount of corn steep liquor and without the at least one antifoaming agent and at least one surfactant, or both. 
 
     
     
       13. The method of  claim 12 , wherein the corn steep liquor, the at least one antifoaming agent, and the at least one surfactant are premixed prior to addition for the culturing. 
     
     
       14. The method of  claim 12 , wherein the corn steep liquor, the at least one antifoaming agent, and the at least one surfactant are individually added for the culturing. 
     
     
       15. The method of  claim 12 , wherein the at least one antifoaming agent is at least one organic antifoaming agent. 
     
     
       16. The method of  claim 15 , wherein the at least one antifoaming agent is a surfactant that has a hydrophilic-lipophilic balance (HLB) value of from about 1 to about 5. 
     
     
       17. The method of  claim 12 , further comprising introducing additional nutrient composition comprising corn steep liquor, at least one antifoaming agent, and at least one surfactant, which is contained in the fermentable biomass. 
     
     
       18. The method of  claim 17 , wherein the corn steep liquor, the at least one antifoaming agent, and optionally the at least one surfactant are premixed prior to addition to the fermentable biomass. 
     
     
       19. The method of  claim 17 , wherein the corn steep liquor, the at least one antifoaming agent, and optionally the at least one surfactant are individually added for the fermentable mass. 
     
     
       20. The method of  claim 12 , wherein the at least one bioproduct is ethanol, oil, or a combination thereof. 
     
     
       21. The method of  claim 12 , wherein the separating comprises a) distilling ethanol from the fermented biomass, b) extracting oil from the fermented biomass, or c) both a) and b). 
     
     
       22. The method of  claim 12 , wherein the fermenting is a high gravity fermentation at from 30% to 40% fermentable solids, and addition of the nutrient composition results in an increased ethanol yield of at least 2% w/v as compared to the ethanol yield wherein the culturing is done with the same amount of urea in place of the nutrient composition. 
     
     
       23. The method of  claim 12 , wherein the propagation and fermentation tanks comprises an ethanol concentration of 0.02% to 18% w/v, and addition of the nutrient composition results in an increased yeast concentration in the fermented biomass of at least 2.5% on a cells per unit weight basis as compared to a yeast concentration in the fermented biomass wherein the culturing is done with addition of only the same amount of said corn steep liquor and without the at least one surfactant and the at least one antifoaming agent. 
     
     
       24. The method of  claim 12 , wherein addition of the nutrient composition results in decreased residual sugar concentration in the fermented biomass of at least 3% w/v as compared to a residual sugar concentration in the propagation and fermentation tanks wherein the culturing is done with addition of only the same amount of said corn steep liquor and without the at least one antifoaming agent. 
     
     
       25. The method of  claim 12 , wherein culturing is performed in a fermentation mode selected from batch fermentation, fed-batch fermentation, or continuous fermentation. 
     
     
       26. The method of  claim 12 , wherein fermenting is performed in a fermentation mode selected from batch fermentation, fed-batch fermentation, or continuous fermentation. 
     
     
       27. The method of  claim 12 , wherein the fermentation substrate comprises corn, wheat, rye, barley, sorghum, wood, willow and switch grass, corn stover, corn cobs, straw bagasse, sugar cane, molasses, sugar beet, tapioca (cassava), potatoes, paper and pulp mills waste, algae, wood, seeds, grasses, or any combination thereof. 
     
     
       28. The method of  claim 12  wherein the fermentation substrate comprises corn.